Problem Diagnosis - Expert Oracle RAC Performance Diagnostics and Tuning - page 605

DB-online mode means the check can be run while the database is open (i.e., in OPEN mode
or MOUNT mode).
DB-offline mode means the check can be run when the instance is available but the
database itself is closed (i.e., in NOMOUNT mode).
Not all checks can be run online and offline. Some checks can be run only internally (database is online),
indicated by the INTERNAL_CHECK column, and some when the database is offline, indicated by the OFFLINE_CAPABLE
column. Checks that are marked as “ASM” in the CLS_COLUMN should be run from an ASM instance.
The following output lists all the checks and their descriptions:
NAME DESCRIPTION
------------------------------ ------------------------------------
HM Test Check Check for health monitor functionality
DB Structure Integrity Check Checks integrity of all database files
CF Block Integrity Check Checks integrity of a control file block
Data Block Integrity Check Checks integrity of a data file block
Redo Integrity Check Checks integrity of redo log content
Logical Block Check Checks logical content of a block
Transaction Integrity Check Checks a transaction for corruptions
Undo Segment Integrity Check Checks integrity of an undo segment
No Mount CF Check Checks control file in NOMOUNT mode
Mount CF Check Checks control file in mount mode
CF Member Check Checks a multiplexed copy of the control
All Datafiles Check Checks all datafiles in the database
Single Datafile Check Checks a data file
Tablespace Check Check Checks a tablespace
Log Group Check Checks all members of a log group
Log Group Member Check Checks a particular member of a log group
Archived Log Check Checks an archived log
Redo Revalidation Check Checks redo log content
IO Revalidation Check Checks file accessibility
Block IO Revalidation Check Checks file accessibility
Txn Revalidation Check Revalidate corrupted transaction
Failure Simulation Check Creates dummy failures
Dictionary Integrity Check Checks dictionary integrity
ASM Mount Check Diagnose mount failure
ASM Allocation Check Diagnose allocation failure
ASM Disk Visibility Check Diagnose add disk failure
ASM File Busy Check Diagnose file drop failure
Running Checks
HM checks can be executed either online using EM, or manually using Oracle provided PL/SQL packages. Oracle
provides two procedural language PL/SQL procedures to manually execute this operation: 1) DBMS_HM.RUN_CHECK and
2) DBMS_HM.GET_RUN_REPORT (discussed under “V$HM_RUN” later in this section).
1. DBMS_HM.RUN_CHECK
The RUN_CHECK procedure is used to manually execute checks at the component level of the database. The
RUN_CHECK is executed using the following syntax:
EXEC DBMS_HM.RUN_CHECK('Dictionary Integrity Check','MV_DFRUN1');